Hard drive storage has increased dramatically over the past few decades. In the early days of personal computing, hard drives were measured in megabytes (MB) or gigabytes (GB). Now, consumer hard drives are routinely available in terabytes (TB), with some models offering 10TB or more of storage space.
What is Hard Drive Storage?
A hard disk drive (HDD) is a data storage device used in computers and other devices. It contains one or more platters to which data is written using a magnetic head, which moves rapidly over the platters as they spin. The platters themselves are made of a non-magnetic material, usually aluminum alloy or glass.
Hard drives come in two main sizes: 3.5-inch and 2.5-inch. 3.5-inch drives are designed for desktop computers, while 2.5-inch drives are made for laptops. The numerical measurement refers to the diameter of the platter inside the drive.
History of Hard Drive Storage Capacity
In the early days of computing, storage capacity was extremely limited. The first hard disk drive was introduced by IBM in 1956 and could store just 5MB of data. By 1980, typical hard drive capacities were still only 10-30MB.
The 1980s and 90s saw rapid increases in hard drive capacity:
- 1980 – 10-30MB
- 1985 – 20-40MB
- 1990 – 80-330MB
- 1995 – 540MB-2GB
- 2000 – 6-20GB
This growth was enabled by improvements in disk platter density through new technologies like giant magnetoresistive (GMR) heads and perpendicular recording.
In the early 2000s, drives reached over 100GB. By 2010, capacities over 1TB were available in mainstream consumer drives. Today, hard drives over 10TB can be purchased by average users.
Largest Consumer Hard Drive
Currently, the largest consumer hard drive is 20TB. These are conventional magnetic recording hard disk drives, not solid state drives.
Here are some examples of 20TB consumer hard drives:
- Seagate IronWolf Pro 20TB
- Western Digital Gold 20TB
- Toshiba MG09ACA20TE 20TB
These 3.5-inch hard disk drives (HDDs) use conventional magnetic recording and sealed helium-filled enclosures to maximize capacity. They sell for $500-$600 each.
Prior to the availability of 20TB models in 2022, the largest drives were 16TB and 18TB units. The increased platter density enabling the jump to 20TB came from technologies like microwave assisted magnetic recording (MAMR).
Largest Data Center Hard Drives
For enterprise and data center applications, even larger capacity drives are available. These are designed for server storage arrays, network attached storage (NAS), and backup systems where high capacity and reliability are critical.
Here are some current models of data center hard drives over 20TB:
- Seagate Exos X20 20TB
- Western Digital Ultrastar DC HC570 20TB
- Toshiba MG09SCA 20TB
These 3.5-inch data center HDDs use shingled magnetic recording (SMR) and sealed helium environments to offer capacities up to 20TB in a standard drive form factor. They are more expensive than consumer drives, selling for $600-$700 each.
Looking beyond 20TB, Seagate has announced plans to release 30TB+ SMR hard drives within the next few years. This will be enabled by new technologies like heat assisted magnetic recording (HAMR).
Largest Solid State Drives
For solid state drives (SSDs) which use flash memory chips rather than magnetic platters, the largest consumer drives today are around 16TB. These drives are prohibitively expensive for most consumers, selling for thousands of dollars.
Here are some examples of high capacity solid state drives:
- Samsung PM1643 30.72TB SSD
- Seagate Exos X16 16TB SSD
- Micron 5210 ION 16TB SSD
For data center and enterprise use, these SSDs offer high speed and throughput combined with capacities rivaling top-end hard disk drives. The Samsung PM1643 drive boasts a staggering 30.72TB of flash storage.
SSD capacities are expected to continue growing rapidly in coming years. However, SSD pricing remains a major barrier for widespread consumer adoption at the highest capacities.
Factors Influencing Maximum Hard Drive Size
There are several technical factors that influence the maximum possible size for hard disk drives currently and into the future:
Platter Density
– Higher areal density means more data capacity per platter. Increasing density has been key to growing capacities.
Number of Platters
– More platters in the same drive size increases total capacity. However, adding platters increases complexity.
Recording Technologies
– New recording methods like SMR, MAMR, HAMR, etc. boost density by allowing smaller magnetic regions on the platters.
Materials and Manufacturing
– Better platter substrates, read/write heads, lubricants, and other advances contribute to higher capacities.
Error Correction
– More robust error checking and correction allows drives to operate with higher data density.
Helium vs. Air
– Using helium instead of air in shielded enclosures reduces drag on platters and allows tighter spacing.
Mechanical Size Limits
– There are limits to how many platters can fit and move precisely within standard drive form factors.
Hard Drive Size History and Future Projections
This table summarizes the growth of maximum hard drive capacities over time, and projects future milestones:
| Year | Max Capacity | Technology/Notes |
|---|---|---|
| 1980 | 10MB | Early HDDs |
| 1990 | 1GB | Beginning of rapid growth |
| 2000 | 100GB | Desktop drives |
| 2010 | 3TB | Perpendicular recording |
| 2020 | 20TB | MAMR, Helium |
| 2025 | 50TB+ | HAMR, Multi-Actuator |
| 2030 | 100TB? | Bit patterned media? |
Hard drive capacities should continue growing rapidly thanks to new technologies. However, there are challenges ahead like the superparamagnetic limit that may cap growth in the 2030s barring a major breakthrough. Hard drives will also face increasing competition from higher capacity solid state storage.
Challenges to Increasing Hard Drive Size
While new technologies are enabling continued growth in hard drive capacities, there are physical limits that may be reached in the coming decades:
Superparamagnetic Limit
– This theoretical limit is where data bits become thermally unstable at high densities. Some analysts say it will be reached in the 2030s at around 100TB.
Complexity Wall
– As areal density increases, more platters and heads are required, increasing cost and failure rates.
Mechanical Limits
– There are constraints on mechanical components like the precision of actuator arms and motors as drives shrink.
Power and Heat
– More platters and smaller components require more power and generate more waste heat that has to be managed.
New Storage Technologies
– Hard drives face escalating competition from solid state, tape, and other high capacity storage technologies. Hard drives may not remain dominant.
Despite these challenges, ongoing investment and innovation aims to push hard drive sizes higher. But other storage tech like tape and DNA storage may be needed to reach exabyte+ capacities in the long term future.
Conclusion
In summary, the largest hard drives today are around 20TB for conventional magnetic HDDs. This capacity has increased rapidly from megabytes in the earliest drives, enabled by advances like perpendicular recording, helium, SMR, MAMR, and more. In the future, new technologies like HAMR may push capacities to 50TB and beyond in coming years, though physical limits to mechanical drives may be reached by the 2030s. However, hard drives face escalating competition from solid state drives at the highest capacities. While hard drives should hit milestones like 50TB and 100TB, in the long run entirely new storage technologies may be required to reach exabyte or larger capacities.